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Free will not an illusion after all

23 September 2009

By Anil Ananthaswamy

CHAMPIONS of free will take heart. A landmark 1980s experiment that purported to show free will doesn’t exist is being challenged.

In 1983, neuroscientist Benjamin Libet asked volunteers wearing scalp electrodes to flex a finger or wrist. When they did, the movements were preceded by a dip in the signals being recorded, called the “readiness potential”. Libet interpreted this RP as the brain preparing for movement.

Crucially, the RP came a few tenths of a second before the volunteers said they had decided to move. Libet concluded that unconscious neural processes determine our actions before we are …